Abstract:
To analyze the characteristics of standard Thai tones, namely, fundamental frequency, fundamental frequency range and duration, produced by Japanese speakers with high and low experience in Thai in comparison to those of Thai native speakers. This research was conducted by having the participants produce a set of monosyllabic words in citation forms and in devised sentences in order to show how Japanese speakers with varying experience in Thai produce the Thai tones, and how the Thai tones produced by Japanese speakers are perceived by Thai native speakers. The data was collected from 15 male informants aged between 19-34 years. The informants were divided into three groups: five native Thai speakers, five Japanese speakers with low experience in Thai and five Japanese speakers with high experience in Thai. The informants were asked to produce 15 Thai words and 15 sentences containing the same 15 Thai words. To examine the acoustic characteristics of tones produced by the informants, Praat v.5.1.07, Python v.2.5, Microsoft Excel 2003 and SPSS for Windows v.16 were used for the acoustical measurements and statistical analyses. The results showed that the acoustic characteristics of the five tones could be classified into two major categories: the static tones (the mid tone and the low tone) and the dynamic tones (the high-falling tone, the mid-rising tone and the low-rising tone). In citation forms, it was found that the Japanese speakers with different experience in Thai produced some tones differently. However, some of the Japanese speakers were able to do well, i.e. the acoustic characteristics of the five tones were similar to those produced by Thai native speakers. In sentences, it was found that the Japanese speakers with high experience in Thai could not make distinctions between the mid tone and the low tone and between the mid-rising tone and the low-rising tone. For those with low experience in Thai, there was a wide range of problems varying across individual speakers. For example, some could not produce the mid-rising tone as a dynamic or contour tone. With regard to the pairs of correspondent tones, it was found that the Japanese speakers with low experience in Thai could not distinguish the mid tone from the low tone, the mid tone from the mid-rising tone, and the mid-rising tone from the low-rising tone. The results of the perception test indicated that the tones in citation forms produced by the Japanese speakers in both groups could be quite well perceived by the Thai listeners but those produced by the Japanese with high experience in Thai could be perceived better. On the other hand, the tones of the words appearing in the devised sentences produced by the Japanese speakers with high experience in Thai were less perceived than those produced by the Japanese speakers with low experience. The Thai listeners were confused between the mid tone and the low tone, and between the mid-rising tone and the low-rising tone. The results showed that the perception study corresponded very well with the acoustic study.